Do extracts of ginkgo biloba increase symptoms of anxiety in depressive patients treated with fluox

Fråga: Do extracts of ginkgo biloba increase symptoms of anxiety in depressive patients treated with fluoxetine? This question concerns a depressed patient previously treated with venlafaxine which was withdrawn because of tinnitus. The patient was recommended by a physician to try ginkgo biloba against the tinnitus. Now fluoxetine treatment of the depressive disorder is considered.

Sammanfattning: There is neither documentation about interactions between ginkgo biloba and fluoxetine in general nor about increased anxiety in depressed patients in particular. In fact, there are no known drug interactions caused by ginkgo biloba at all.

Svar: The question concerning gingko biloba and its interactions with other medicines has earlier been discussed (1-3). The documentation concerning ginkgo biloba and interactions is sparse. Despite the fact that ginkgo biloba is often used in patients who are taking many other drugs, there are no known drug interactions (4).

Gingko biloba is thought to exert its pharmacological effects through vasodilatation of arteries, antagonism of platelet activating factor and prevention of membrane damage caused by free radicals. The traditional uses of ginkgo are for peripheral vascular disease such as intermittent claudocation and cerebral insufficiency with difficulties of concentration and memory, absent mindness, confusion, lack of energy, tiredness, decreased physical performance, depressive mood, anxiety, dizziness, tinnitus and headache (4,5,6).

The only published report on combined treatment with fluoxetine and gingko biloba is a case of fluoxetine-induced genital anaesthesia which was successfully treated with ginkgo biloba extract (7).